Method for audiovisual signal synchronization and audiovisual synchronization processing system

Abstract

A method and a system for audiovisual signal synchronization are provided. The method is adapted to an audiovisual system. When the audiovisual system is in operation, a circuit for distributed audiovisual synchronization-calibration is provided for acquiring delay information reported by various audiovisual circuit modules that are in charge of processing audiovisual signals. Accordingly, the audiovisual synchronization processing system that is disposed in the audiovisual system to synchronize the audiovisual signals can obtain a time difference between audio signals and video signals. When processing audio and video data, the audiovisual system can utilize the time difference to synchronize the audio signals and the video signals, and then output an audiovisual content.

What is claimed is: 
     
         1 . A method for audiovisual signal synchronization, which is adapted to an audiovisual system, comprising:
 receiving audio and video data after turning on an audiovisual device or switching to an audiovisual channel;   collecting, by a circuit for distributed audiovisual synchronization-calibration of the audiovisual system in a distributed manner, delay information provided by one or more audio processing circuits that are activated on an audio processing path and is used to process audio signals in the audiovisual system and one or more video processing circuits that are activated on a video processing path and is used to process video signals in the audiovisual system, wherein, a processing circuit for audiovisual signal synchronization of the audiovisual system checks one or multiple ones of the one or more audio processing circuits and the one or more video processing circuits that is activated to process the audio signals and the video signals in the audio and video data;   calculating a time difference between the audio signals and the video signals in the audio and video data according to the delay information; and   performing an audio and video data processing procedure to calibrate the audio signals and the video signals, and outputting an audiovisual content after synchronizing the audio signals and the video signals according to the time difference;   wherein the delay information obtained by the circuit for distributed audiovisual synchronization-calibration is used to establish a lookup table, which includes an audio processing time table that records a processing time of the one or more audio processing circuits for processing the audio signals, and a video processing time table that records a processing time of the one or more video processing circuits for processing the video signals;   wherein the lookup table is established by steps of:
 preparing an audio and video sample; 
 inserting an audiovisual mark into the audio and video sample; 
 measuring, based on the audiovisual mark, the processing time of the one or more audio processing circuits and the processing time of the one or more video processing circuits for processing the audio signals and the video signals of the audio and video sample on the audio processing path and the video processing path, respectively; and 
 establishing the lookup table. 
   
     
     
         2 . The method according to  claim 1 , wherein the circuit for distributed audiovisual synchronization-calibration further obtains, in real time, a time for a digital signal processor of the audiovisual system to process the audio and video data, and the time is integrated into the delay information, so that the circuit for distributed audiovisual synchronization-calibration takes the time spent by the digital signal processor into account during calibration of the audio and video data. 
     
     
         3 . The method according to  claim 1 , wherein a system clock signal of the audiovisual system is used to measure the processing time of each of the one or more audio processing circuits or the one or more video processing circuits based on the audiovisual mark. 
     
     
         4 . An audiovisual synchronization processing system, which is disposed in an audiovisual system, comprising:
 a processing circuit for audiovisual signal synchronization; and   a circuit for distributed audiovisual synchronization-calibration;   wherein the processing circuit for audiovisual signal synchronization operates a method for audiovisual signal synchronization, and the method includes:
 receiving audio and video data after turning on an audiovisual device or switching to an audiovisual channel; 
 collecting, by the circuit for distributed audiovisual synchronization-calibration in a distributed manner, delay information provided by one or more audio processing circuits that are activated on an audio processing path and is used to process audio signals in the audiovisual system and one or more video processing circuits that are activated on a video processing path and is used to process video signals in the audiovisual system, wherein, the processing circuit for audiovisual signal synchronization of the audiovisual system checks one or multiple ones of the one or more audio processing circuits and the one or more video processing circuits that is activated to process the audio signals and the video signals in the audio and video data according to format data of the audio and video data according to format data of the audio and video data; 
 calculating time difference between the audio signals and the video signals in the audio and video data according to the delay information; and 
 performing an audio and video data processing procedure to calibrate the audio signals and the video signals, and outputting, by the audiovisual system, an audiovisual content after synchronizing the audio signals and the video signals according to the time difference; 
 wherein the delay information obtained by the circuit for distributed audiovisual synchronization-calibration is used to establish a lookup table, which includes an audio processing time table that records a processing time of the one or more audio processing circuits for processing the audio signals, and a video processing time table that records a processing time of the one or more video processing circuits for processing the video signals; 
 wherein the lookup table is established by steps of:
 preparing an audio and video sample; 
 inserting an audiovisual mark into the audio and video sample; 
 measuring, based on the audiovisual mark, the processing time of the one or more audio processing circuits and the processing time of the one or more video processing circuits for processing the audio signals and the video signals of the audio and video sample on the audio processing path and the video processing path, respectively; and 
 establishing the lookup table. 
 
   
     
     
         5 . The audiovisual synchronization processing system according to  claim 4 , wherein, after the audio and video data is processed by the audiovisual synchronization processing system, the time-compensated audio signals and the time-compensated video signals are separately generated, and then the audiovisual content is outputted via an audio output circuit and a video output circuit of the audiovisual system. 
     
     
         6 . The audiovisual synchronization processing system according to  claim 4 , wherein the circuit for distributed audiovisual synchronization-calibration further obtains a time to process the audio and video data by a digital signal processor of the audiovisual system in real time, and the time is integrated into the delay information for the circuit for distributed audiovisual synchronization-calibration to additionally consider the time spent by the digital signal processor when calibrating the audio and video data. 
     
     
         7 . The audiovisual synchronization processing system according to  claim 4 , wherein the audiovisual system relies on a system clock signal and the audiovisual mark to measure the processing time of each of the circuit or software modules.